1. Field of the Invention
The present invention relates to an automatic paper feeder, and more particularly to an integrated paper presser and stopper for an automatic paper feeder.
2. Description of the Prior Art
An automatic paper feeder is frequently included in various kinds of office automation equipment, such as image-scanning device, photocopier, printer, etc., so that paper sheets to be scanned, copied or printed could be automatically separated and fed via the automatic paper feeder. FIG. 1 illustrates a scanner 1 and a conventional automatic paper feeder 2 associated therewith. The scanner 1 is internally provided with an optical scanning module 11, a pair of guide bars 12, and related optical components, such as focusing lens, image sensor, driving mechanism, etc. The optical scanning module 11 is moved along the guide bars 12 under control of a control circuit of the scanner 1, and a sheet of paper 3 to be scanned is fed with the automatic paper feeder 2 for image scanning.
FIG. 2 shows an internal structure of the automatic paper feeder 2 of FIG. 1. The automatic paper feeder 2 mainly includes a paper tray 21, a paper feeding roller 22, a paper pressing plate 23, a stopping plate 24, a paper separating mechanism 25, and a paper separating plate 26. Paper sheets 3 to be fed are stacked on the paper tray 21 and held in place under a pressure applied by the paper pressing plate 23 on the paper sheets 3. Meanwhile, lower ends of the stacked paper sheets 3 are positioned against the stopping plate 24. A main function of the paper separating mechanism 25 is to provide a proper gap between the stopping plate 24 and the paper feeding roller 22 and to apply a proper pressure against the paper separating plate 26.
When the paper feeding roller 22 rotates, it brings a lowermost sheet of paper 3 in the paper tray 21 to move in a direction indicated by arrow I toward the gap between the paper feeding roller 22 and the paper separating plate 26. In the event two or more sheets of paper 3 are fed toward the gap, a difference between the friction coefficients of the paper feeding roller 22 and the paper separating plate 26 would allow only the paper in contact with the paper feeding roller 22 to move through the gap. Therefore, the stacked paper sheets 3 could be separately fed for scanning one by one.
In the conventional automatic paper feeder 2 having the above-described structure, separated paper pressing plate 23 and stopping plate 24 are provided to compressively hold and stop, respectively, paper sheets 3 stacked on the paper tray 21. These two components are mounted in the automatic paper feeder 2 through their respective fixing mechanisms, and therefore complicate the structure of the automatic paper feeder 2.
Number of paper sheets 3 stacked on the paper tray 21 varies depending on actual needs. When there are more sheets of paper 3 stacked on the paper tray 21 for subsequent process, more units of stopping plate 24 might be required to stop the stacked paper sheets 3 at different stages. However, the automatic paper feeder would become more complicate in its structure and assembling when several stopping plates 24 are to be included in its very limited internal space.
Therefore, it is desirable to develop a paper pressing and stopping structure that does not complicate the whole structure of the automatic paper feeder and the assembling thereof.
A primary object of the present invention is to provide an integrated paper presser and stopper for an automatic paper feeder, so that a reduced space is needed in the automatic paper feeder to effectuate the functions of pressing and stopping paper sheets stacked on the paper tray.
Another object of the present invention is to provide an integrated paper presser and stopper for automatic paper feeder that may include increased number of paper stopping sections to achieve enhanced paper stopping effect when there are a large amount of paper sheets stacked on the paper tray. The provision of multiple paper stopping sections on a one-piece paper presser and stopper also reduces difficulties in subsequent separation of paper sheets.
To achieve the above and other objects, the structure according to the present invention mainly includes a fixing section, a paper pressing section downward extended from the fixing section at an inclined angle toward a paper-out end of the paper tray, a first bent section formed at a lower end of the paper pressing section to define a first gap, a paper stopping section downward extended from the first bent section at an inclined angle toward the pauper-out end of the paper tray, and a second bent section formed at a lower end of the paper stopping section to define a second gap which is smaller than the first gap. Preferably, a torsional elastic element is further associated with the fixing section to provide the integrated paper presser and stopper with a compression stress.